Swing mechanism for cranes and the like



y 25, 1965 J. D. SCHELL 3,184,980

SWING MECHANISM FOR CRANES AND THE LIKE Filed Dec. 28, 1962 3 Sheets-Sheet 1 INVENTOR JAMES D. SCHELL BYQKMM ATTORNEY May 25, 1965 J. D. SCHELL SWING MECHANISM FOR CRANES AND THE LIKE 3 Sheets-Sh et 2 Filed Dec. 28, 1962 INVENTOR JAMES SCHELL BY E 6 FIG. 2

ATTORNEY May 25, 1965 J. D. SCHELL 3,184,980

SWING-MECHANISM FOR CRANES AND THE LIKE Filed Dec. 28, 1962 INVENTOR.

JAMES D. SCHELL Q 4 MM ATTORN EY United States Patent 3,184,980 SWING MECHANISM FUR CRANES AND THE LEKE .iames D. Schell, Battle Creek, Mich, assiguor to Clark Equipment Company, a corporation of Michigan Filed Dec. 28, 1262, Ser. No. 248,115 6 Claims. (ill. 74-1il2) This invention relates to swing mechanisms, and more specifically to such a mechanism for use with a crane or the like and including extensible type actuators.

Various types of swing mechanisms for cranes and the like are known. However, many prior such mechanisms are incapable of actuating a crane or boom through an arc of up to 180". While meshing gear and turntable types of swing mechanisms are capable of pivoting a crane through large arcs of movement, they tend tobe relatively expensive. Swing mechanisms which do not depend upon gears and turntables, but utilize linkage constructions, have heretofore tended to be undesirably bulky and are frequently incapable of providing equal or adequate power at the end portions of arcuate travel of the crane. It is therefore one of the objects of the present invention to provide a swing mechanism of the type contemplated which is compact, economical, and which provides equal and adequate power during movements of the mechanism in the extreme ranges of movement thereof.

It is another object of my invention to provide an improved and relatively inexpensive swing mechanism which is capable of pivoting a crane or the like through a relatively large arc of movement.

In carrying out my invention in a preferred embodiment thereof I provide a pair of extensible piston and cylinder type actuators connected to a stationary support member. The upright standard of a crane or other swingable device is journaled in the stationary support member for pivotal movement about a vertical axis. The crane standard is connected to the piston and cylinder actuators by a first linkage connected to one of the actuators and by a second linkage which is reversed from the first linkage and connected to the other of the actuators so that retraction of one of the actuators and extension of the other actuator causes the upright standard of the crane to pivot in one direction, and a reversal of the actuation of the actuators causes the upright standard of the crane to pivot in the opposite direction.

The above and other objects, advantages and features of my invention will become apparent to persons skilled in the art from the following detailed description taken in conjunction with the drawing wherein:

FIGURE 1 is a rear elevational view of a portion of a vehicle upon which a crane is mounted and embodying my invention;

FIGURE 2 is a partial sectional view on an enlarged scale taken along line 2-2 of FIGURE 1 with the swing mechanism positioned midway between extreme positions of travel; and

FIGURE 3 is similar to FIGURE 2 with the swing mechanism actuated to one of its extreme positions of travel.

Referring now to FIGURE 1, the numeral denotes generally a portion of a vehicle including a pair of rubbertired wheels 12 carried at the outer end of an axle 14 which supports a frame 16. Mounted upon frame 16 ice is a stationary support structure 18 which supports a crane or the like and the swing mechanism therefor. Support structure 18 includes a pair of side plates 20 connected to frame 16 at 21, a brace plate 22 and a top plate 24% which serves as a bearing surface as will be explained shortly. Disposed below brace plate 22 are three horizontally disposed and vertically spaced plates 42, 44 and 46 which are secured to a back plate 48 and side plates 2i). lPlates 42 and 34 are U-shaped, as may be seen from FIGURES 2 and 3. The stationary support structure 18 also includes a vertically disposed tubular member 26 which extends downwardly from the top plate 24 beyond plate 42. It will be noted that tubular member 26 is disposed so that the bore 28 thereof coincides with an opening 36 in plate 24. The entire structure 13 preferably is welded, although other means of fabrication may be employed.

Rotatably journaled in and carried by stationary support structure 18 is a crane or the like, of which only a portion of the upright standard 32 is shown. The standard 32 includes a tubular wall portion 34, an annular plate 36 preferably welded to the bottom end of wall portion 34, and a rod member 38 which is secured to plate 36 and extends downwardly therefrom through opening 34 and bore 28, beyond the end of tubular member 26 and through an annular opening 5G in plate 46. At this point it will be appreciated that upright standard 52 bears on plate 24 and is maintained in position by the cooperation of rod 38 with tubular member 26, and further that there is sufiicient clearance between rod 38 and bore 23 to permit pivotal movement of upright standard 32.

Referring now also to FIGURES 2 and 3, the crane or the like may be actuated from one extreme position through an arc of approximately 180 to a second extreme position by means of a swing mechanism 40 which includes a double-acting fluid motor 52 disposed between plates 42 and 44 and a linkage 60. Fluid motor 50 includes a cylinder 54 which is pivotally connected to back plate 48 by means of a bracket and pin connection 56, a piston (not shown) slidably disposed within cylinder 54 and a piston rod 58 which is connected to the piston and extends through one end of cylinder 54. The outer end of piston rod 53 is connected to rod 38 of the upright standard 32 by means of linkage 60 so that actuation of fluid motor 52 causes pivotal movement of rod 38 and hence of upright standard 32.

Linkage 60 includes a lever member or bar 62 which is pivotally mounted on a shaft 64 which extends vertically between plate 42, 44 and 4.6. Lever 62 is disposed approximately midway between plates 42 and 44 by means of two pairs of annular spacer and bearing members 66. One end of lever 62 is connected to the outer end of piston rod 58 by means of a pin and bracket connection 68 and the other end of lever 62 is pivotally connected to a connecting link 79 by means of a pin '72. As will be seen from FIGURE 4, connecting link 72 is made up of a pair of identical bars 74 which are disposed on either side of lever 62. The other end of connecting link 7a is pivotally connected by means of a pin 76 to an arm 78 which is secured to rod 38 and extends radially outwardly therefrom.

Disposed below and spaced laterally from fluid motor 52 and linkage 6i and located between plates 44- and 46 is a fluid motor 86 and linkage 82 for connecting fluid motor 8% to rod 38. As will be noted from FIGURE 2, fluid motor 8% and linkage 32 is an allochiral duplicate of fluid motor 52 and linkage of}. Fluid motor 8% includes a cylinder 84 pivotally connected to back plate 48 by means of a pin and bracket connection 86, a piston (not shown) slida-bly disposed in cylinder 84 and a piston rod 88 which is connected to the piston and extends outwardly through one end of cylinder 84.

Linkage 82 includes a lever member or bar 94? which is pivotally journaled on shaft 6 and held approximately lever 90 is pivotally connected by means of a pin 162 to an arm 1% which is secured to rod 38 and extends radially outwardly therefrom.

In the interest of brevity i have not shown the fluid system for actuating fluid motors 52 and 86 since such systems are conventional, and further form no part of the present invention. A suitable fluid system would include a fluid sump or reservoir, a fluid pump for supplying pressurized fluid from the sump to a four-way control valve and fluid conduits for connecting fluid motors 52 and S0 to the control valve,inciuding flexible conduits where necessary. The fluid conduits arranged to connect opposite ends of cylinders 54 and 84 are in parallel so that when the fluid motors 52 and 80 are actuated one of them extends while the other retracts.

. pivotal member and extending outwardly therefrom, a lever pivotally connected intermediate the ends thereof to the support structure and pivotally connected adjacent one end thereof to the respective fluid motor and a connecting link pivotally connected to the outer end of said arm and to the other end of said lever, the pivotal connections of said leversto the'support structure being substantially coaxial and disposed intermediate said fluid motors.

2. For use with a vehicle having a support structure and equipped with load handlingmeans including a trunnion member pivotally journaled in the support structure, a swing mechanism for. pivoting the load handling means through a relatively large arc comprising a first piston and cylinder fluid motor connected to. the support structure and disposed on one side of the trunnion member, a second piston and cylinder fluid'motor connected to the support structure and disposed on the other side of the trunnion member, first linkage means for connecting said first motor andthe trunnion member, said first linkage means being disposed substantially on the 'said other side of the trunnion member to permit pivotal movement of the load handling means throughan arc from one side to the other side of the vehicle, and second linkage means for connecting said second motor and the trunnion member, said. second linkage means being disposed substan- V tially on the said one side of the trunnion mmeber to per- Turning now to the operation of my invention, it will be assumed that it is desired to pivot upright standard 32 from the centered position shown in FIGURES 1 and 2 to the one extreme position shown in FIGURES In order to accomplish this movement of upright standard 32 the operator manipulates the control valve to admit pres- 72 while a counterclockwise push is being exerted on arm liM-through connecting link 96 and lever 90 due to the extension of fluid motor 8%). Counterclockwise move- I ment (as seen in FIGURES 2 and 3) of upright standard 32is accomplished merely by manipulating the control valve to extend fluid motor 52 and retract fluid motor 80;

It will now be seen that I have provided a swing mechanism which provides an equal amount of power at each end of travel through a large arc of movement by superimposing two linkage systems which are allochiral duplicates, Further, it will be noted that the swing mechanism may be maintained in any intermediate position between the two extreme positions merely by hydraulically locking fluid motors 52 and 89.

The above-detailed description of a preferred embodiment of my invention is intended to'be illustrative only, and therefore the limits of my invention should be determined solely fromthe following appended claims taken in view of the prior art.

I claim:

1. For use with a support structure and a member.

mit pivotal movement of the load handling means through an are from one side to the other side of the vehicle, the said linkage means being symmetrically related to provide adequate and approximately equal power at the extremes of arcuate movement .of the load handling means.

3. A swing mechanismas settorth in claim 1 wherein the said linkage means are pivotally connected to the support structure, said pivotal connections being substantially coaxial. V

v 4. A swing mechanism as set forth in claim 1 wherein said first linkage means includes an arm connected to the trunnion member which extends outwardly therefrom in a direction away fromsaid first motor and said second linkage includes an arm connected to the trunnion mem her which extends outwardly therefrom in a direction away from said second motor. 7

5. For use'with asupport structure and a" member journaled in the structure for pivotal movement, a swing mechanism comprising first and second fluid motors connected to the support structure so that the pivotal member is intermediate said motors, and first and second linkages connecting said first and second fluid motors, respectively, and the pivotal member, said first fluid motorand linkage and said second fluid motor and linkage being spaced vertically apart and having an allochiral relation to each other, each linkage including an armsecured to the pivotal member and extending outwardly therefrom, a lever pivotally connected to the support structure and re spective fluid motor and a connecting link pivotally connected to said arm and said lever, the pivotal connection of said lever to said support structurebeing located intermediate the pivotal connections to the connecting link and to the respective fluid motor.

6. For use, with a support structure, a swing mechanism 7 comprising first and second motor means connected to ing piston and cylinder type fluid motors connected to the a support structure and disposed so that the pivotal memher is intermediate said motors and first and second linkbeing vertically spaced apart and allochirally related to each other, each linkage including an arm secured to the i ages connecting respectively said first and second fluid I the support structure on opposite sides of the pivotal member, a first arm connected to the pivotal member and extending outwardly therefrom in a direction away from said first motor means, a second arm connected tothe, pivotal member and extending outwardly therefrom in .a direction away from said second motormeans, said first and second arms extending outwardly from the pivotal member on opposite sides of the pivoted member, first linkage means connecting said first arm and first motor means, and second linkage meansconnecting said second arm and second motor means, said first linkage means including a lever pivotally connected to said first motor meansand a link pivotally connected to said lever and said first arm, said lever also being pivotally connected to the support structure intermediate the pivotal connections thereof to said first motor means and link, said second linkage means including a lever pivota-lly connected to said second motor means and a link pivotally connected to said last-mentioned lever and said second arm, said last-mentioned lever also being pivotally connected to the support structure intermediate the pivotal connections thereof to said second motor means and link.

References (Iited by the Examiner UNITED STATES PATENTS Armington 18079.2 Van Weenen 9268 XR Ireland.

Quayle 180-792 Stummer 212-66 10 BROUGHTON G. DURHAM, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,184,980 May 25, 1965 James D. Schell It is hereby certified that error appears in the above numbered patent reqiiring correction and that the said Letters Patent should read as correctedbelow.

Column 2, line 37, for "50" read 52 column 4, line 27, for "mmeber" read member column 4, lines 34 and 38, for the claim reference numeral "1'', each occurrence, read Signed and sealed this 19th day of October 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Ancsting Officer Commissioner of Patents 

1. FOR USE WITH A SUPPORT STRUCTURE AND A MEMBER JOURNALED IN THE SUPPORT STRUCTURE FOR PIVOTAL MOVEMENT, A SWING MECHANISM COMPRISING FIRST AND SECOND DOUBLE-ACTING PISTON AND CYLINDER TYPE FLUID MOTORS CONNECTED TO THE SUPPORT STRUCTURE AND DISPOSED SO THAT THE PIVOTAL MEMBER IS INTERMEDIATE SAID MOTORS AND FIRST AND SECOND LINAGES CONNECTING RESPECTIVELY SAID FIRST AND SECOND FLUID MOTROS AND THE PIVOTAL MEMBER, SAID FIRST FLUID MOTOR AND LINKAGE AND SAID SECOND FLUID MOTOR AND LINKAGE BEING VERTICALLY SPACED APART AND ALLOCHIRALLY RELATED TO THE EACH OTHER, EACH LINKAGE INCLUDING AN ARM SECURED TO THE PIVOTAL MEMBER AND EXTENDING OUTWARDLY THEREFROM, A LEVER PIVOTALLY CONNECTED INTERMEDIATE THE ENDS THEREOF TO THE SUPPORT STRUCTURE AND PIVOTALLY CONNECTED ADJACENT ONE END THEREOF TO THE RESPECTIVE FLUID MOTOR AND A CONNECTING LINK PIVOTALLY CONNECTED TO THE OUTER END OF SAID ARM AND TO THE OTHER END OF SAID LEVER, THE PIVOTAL CONNECTIONS OF SAID LEVERS TO THE SUPPORT STRUCTURE BEING SUBSTANTIALLY COAXIAL AND DIPOSED INTERMEDIATE SAID FLUID MOTORS. 